Detecting device.



G. B GRAY.

DETECTING DEVICE.

APPLICATION FILED APR.25,1912.

Patented June 20, 1916.

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G. B. GRAY.

DETECTING DEVICE,

: APPUCATION FILED APR.25;1912. 1 ,1 8'7, 1 7. Patented June 20, 1916.

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GAEDNER B. GRAY, OF PITTSBURGH, PENNSYLVANIA, ASSIG-NOR, BY MESNE ASSIGN- MEETS, TO AUTOMATIC TRAIN CONTROL &- SIGNAL COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF DELAWARE.

DETECTING DEVICE.

Specification of Letters Patent.

Patented June 2@, 1%16.

Application filed April 25, 1912. Serial no. 693,157.

To all whom it may concern:

Be it known that l, GARDNER B. GRAY, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Detecting Device, of which the following is a specification.

The present invention relates to improvements in a differential relay detect ng device, the primary object of the invention being the provision of a novel arrangement and disposition of a differential relay in connection with circuits leading to an engine equipment in an electric signal and control system, more especially set forth n a copending application filed on even date herewith, bearing the Serial No. 693,156.

The difierential relay is so disposed in the primary circuit of a train control system, such as above mentioned, as to protect against grounds and crosses in the different circuits of the engine equipment, the same being conveniently disposed between the insulated and non-insulated wheels of the engine which complete a primary circuit through av section of the traffic track. Any sneaking off or shunting of the currents in the primary circuit in other directions than desired will immediately cause one or the other of the coils of the differential relay,

due to a breakdown in the insulation, a cross or otherwise, to open the circuit to the main controlling relay, as will later appear, so

that the locomotive or train will be brought to a full stop due to the setting of the'air brakes or the cutting-off of the steam. By

this means of protection, in combination with the insulated plates carried by the locomotive draw bar and the truck frame, the wiring in the cab of the locomotive is automatically protected agalnst all possible crosses or grounds so that it is impossible to obtain in the system a false clear indication, as any severing of the wiring or grounding will produce a danger eflect .upon the system and bring the train or locomotive to a.

stop. 4

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combi nation and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the one relay to the other.

invention herein disclosed can be made within the scope of what is claimed without departing from the spirit of the invention.

In the drawings: Figure 1 is a diagrammatic view illustrating the complete primary circuit of the control system with the differential relay so disposed therein as to exercise a control over a circuit energizing a main controlling or danger relay. Fig. 2 is a diagrammatic view showing in detail the construction of the differential relay. Fig. 3 is a view taken on line 3-3 of Fig. 2.

Like reference characters refer to corresponding parts throughout the specification and drawings. I

Referring to Fig. 1 of the drawings, which illustrates a primary circuit of a train control system, the numeral 1 designates a low voltage primary battery located upon the engine for supplying current to the primary circuit. 1 designates a similar battery which may be thrown in usein case of breakage or non-efficiency of the other of said batteries. These batteries are to be of a comparatively low Voltage to prevent the creeping of the current through the ties from Current flows from the positive side of battery 1 through the conductor 2 to the contact 3 of the reversing switch S. Normally engaging the contact 3 is the arm 4 of said switch and through which the current flows to the conductor 5 to the winding 47 of the coils 6 and 6* of the difl'erential relay W. Current then flows from the coil 6 through the conductor 7 to the wheels 8 of the locomotive through the track to the wheels 9 of the tender, conductor 10 to the winding 48 of the coils 6* and 6 of the differential relay W. From this winding of the relay W current flows through the conductor 11, member 12 of the reversing switch S, which is normally engaging with the contact point 12 thereof, then through conductors 13, 14 and 15 to the caution relay l6 and the polarized relay 17. Under normal conditions the relays 16 and 17 influence their armatures into engagement with their respective contact points. From the drawings it will be seen that the relay 16 controls the armatures 18, 19 and 20 and that the relay 17 controls the armatures 21, 22 and 23. A circuit for normally energizing the caution relay 16 is continued therefrom through conductor 24,

armature 18, contactpoint 25, conductor 26, armature 21, which is normally held into engagement with its contact point 2? by the polarized relay 1?. From the contact point 27 the circuit continues through the common return conductor 28, which is led to the metallic plates 23 disposed between plates of insulation carried by the truck, through the conductor 29 to .the metallic plate 30, carried by the draw bar D of the tender, through the conductor 31 to the negative side of the battery 1. Likewise, a circuit for normally energizing the polarized relay 17 is continued therefrom through conductor 17*, armature 22, contact point 22", conductor 22 tothe common return conductor 28 and therethrough to the battery 1. The above sets forthcertai'nc'i'rcuits of the primary circuit of the train control system which controls the caution signals given to the engineer and the danger signals for applying the brakes and cutting on the motive power of the engine. 7

As is set forth in applicants copending application herein referred to,- after the reception of the caution signal the relays 16 and 17 are reenergized. by the operation of the time valve G, which automatically closes certain pick-up circuits, after the lapse of a predetermined period of time. W hen this valve G moves the Bourdon tubes G and G to bridge the contacts 45, 46 and 47, and 48 and 49 respectively, current is shunted from conductor 24 through conductor 50 to the contacts 47 and 45 which are now bridged as shown in dotted lines, Fig, 1, by the tube G, through conductors 51 and 52, contacts 53 and 54 which are bridged by the tube K, Fig. 1, conductor 55, contacts 49 and 48 now bridged by tube G2, as shown by dotted lines, Fig. 1, through conductors 56, 28, 23, 29, 30 and 31 to the battery 1; this completes the circuit through the relay 16, and thereby the same becomes reenergized and picks up its armatures 18, 19 and'20. Also, the closing of the contacts 45, 46, 47, 48 and 49 causes current from the conductor 17 to shunt through conductor 57, contacts 58 and 59 normally bridged by the time tube K, conductor 60, contacts 46 and 45 now bridged by the tube Gr, conductors 51 and 52, contacts 53'and 54, conductor 55, bridged contacts 49 and 48, conductor 56' to the common return conductor 28, and thereby renergize the polarized relay l'h-which in turn then moves its armatures 21, 22 and 23 to the position shown in full lines, Fig. 1.

Ilt is understood, that the primary circuit ay be ruptured by certain conditions of a track circuit, which is fully set forth in applicants Patent 909,083, patented January 5, 1909, and thereby cause the indication of the caution and danger signals. The circuits (not shown) for controlling the danger signals are suitably fed from a secondary a I I battery and arc-so arranged as to have their currents pass through the armatures 32 which are controlled by the main controlling relay 33.

The relay 33. is fed from the secondary battery Q, which is of a comparatively higher voltage than the batteries 1 and 1, by the following circuit under normal running conditions: from the positive side of the battery, through the conductor 34, armature 19, contact point 35, conductors 36 and 37, armature 38 of the differential relay W, contact 39, conductor 40, relay 33, conductor 41, back to the negative side of the battery Q.

As set forth in applicants application Serial No. 693,156, when the primary circuit is ruptured by certain conditions of the track circuit the caution relay 16 becomes deenergized and drops its armatures 18, 19 and 20, the armature 20 opens a certain circuit for indicating the caution signal and the armature 19 opens the circuit which feedsthe main relay 33, but since the relay 17 is a polarized relay, upon taking thecaution signal, the current through the same will become reversed and the armature 23 thereof will be brought into contact with the point :42, thereby establishing a bypass whereby current will flow from. the battery Q3 through the conductors 34 and 43, contact point '42, armature 23, conductors 44 and 37, armature 38, contact point 39,'conductor 40, relay 33, and conductor 41 to the battery. The above establishes a circuit that will feed the relay 33 and prevent the same from being deenergized on the reception of a cantion signal and the break in its normal circuit by the dropping of the armature 19. As long as the main controlling endanger relay 33 is energized it holds the armature 32 in position to make certain circuits which will render the train controlling full lines, Fig. 1, therefore the normal circult and bypass for feeding the relay 33 are both open and the relay becomes deenergized and drops its armatures 32, thereby causing the train controllingmechanism to operate.

After the reception of a danger signal, only the relay 16 needs to be reenergized to pick up its armatures, since the armatures of the polarized relay 1? have not moved from their normal position. shown in full lines, 'Fig. 1, as fully set forth in applicants application Serial No. 693,156, and wherein it is, also, stated that under the above mentioned conditions the time valve K has caused the tube K to break contact with the points 52, 54, 58 and 59 and the time valve L has caused the tube L to bridge the contacts 61 and 62. By the tube K breaking contact at 53, 54, 58 and 59, the operation of the time valve G will not automatically restore a circuit through the relay 16. However, there is provided means through which the engineer may reenergize the relay 16 by closing the key 63. Since the normal circuit through the relay 16 is only broken by the armature 18 the restoring circuit for the relay may be traced as follows: from the conductor 24 through conductor 50, contacts 47 and 45, conductor 51, contacts 61 and 62, conductor 64, contact 65, key 63, conductor 66, speedometer 67, conductor 68, through the common return 28 to the battery 1.

The above describes the primary circuit, including the pick-up or restoring wires, and a portion of the secondary circuit which is necessary to properly bring out the utility and operation of the differential relay W.

By referring to the conductors 2, 5, 7, 10, 11 and 14 which lead from the positive side of the battery 1 to the relays 16 and 17, it becomes necessary to protect this portion of 'the wiring of the primary circuit against a possible ground or cross. In order to do I this, a differential relay has been introduced into the primary circuit, which. relay is located near the insulated truck of the tender, and the-wires 7 and 10 leading to the two sides have been grounded, one on the engine wheel and the other on the tender wheel, respectively, through the two diflerent coils of this differential relay W, in such a way that any sneaking off or shunting of the current in other directions than passing through the wires 5 and 11 to the ground, will immediately energize one of the coils or the other, as the case may be due to the crossing'o'f one of the circuits, and thus open the circuit of the controlling relay 33 which when deenergized will cause the brakes tov set and the motive power of the train to be cut off. 7 I

The differential relay W consists in the two coils 6 and 6 supported upon the bed 45 and provided with the top plate 46. The windings of each coil of this relay consists of two wires marked .47 and 48 wound parallel but carrying current in opposite directions to each other throughout their whole length. The windings 47 of both coils are connected in series to make one of the differential windings while the windings of the wire 48 are connected in a similar manner to make the other differential winding so that current in either set of windings forms a magnetic field and attracts the armature 38. Now assuming that the train is in normal running condition with no crosses or grounds existing in the wiring of the primary circuits of the cab, current will flow through the two windings 47 and 48 of the two parallel coils of the differential relay W in opposite directions with equal value, and therefore the two magnetic fields balance each other and the resultant field is zero, which causes noattraction of the armature 38. If, however, current in the two parallel windings 47 and 48 is opposite in direction but has not exactly the same value, as would be the case if all the current which goes out through one of the windings does not come back through the other due to the fact that one winding is shunted by a leak of current, then the resultant field is proportionate to the difference in current and even if this difference is not suflicient to interfere in the slightest in the operation of the other apparatus, (the cab relays 16 and 17 in this case)the efl'ect is to lift the armature 38 of the difl erential relay W and so break the normally closed contact 39 and thereby deenergize the relay33 which will give the danger signal that something is wrong and bring the trainto a stop. The windings 47 and 48 of the differential relay W are shown diagrammatically for the purpose of clear illustration and are so disposed to' properly neutralize each other when the currents passing therethrough are equal. The direction of the currents through the windings 47 and 48 is shown by arrow heads and the binding posts are numbered to show the proper connections of the conductors previously described thereto.

The armature 38 of the diiierential relay -W comprises the armature plate at having by the brackets g which are secured to the base 45. Suitable trunnions h adjustably and pivotally hold the rearwardly extending arms '5 of the armature plate a into position and allow the same to rise and fall according to the magnetic influence of the coils 6 and 6 thereoven.

With the presence of the differential relay W in the primary circuit, protection is afforded in the following manner: First consider a ground on conductor 5, as shown in dotted lines X, due, perhaps, to the insulation being worn through, allowing the conductor 5 to come in contact with the iron pipe in which all wires are run. This con tact is the same as a cross between conductor 5 and the engine frame, current going from the battery .1 through the conductor 2, re

versing switch S, conductor 5, to the ground, as indicated by the line X. From this point X part of the current flows through the windings 47 of the coils of the differential relay W, wire 7 to the engine frame, while the remainder of the current takes a short cut to the engine frame by means of the ground at X, so it is evident that the winding 47 of the coils will not have the benefit of all the current flowing through the conductor 5. However, all the current flowing through the conductor 5 to the point X will flow through the windings 48 of the difi'erentialrelay as follows: from the engine frame or wheels 8 to the track, tender truck 9, conductor 10, winding 48 of the relay W, conductor 11, reversing switch S, conductors 13 and 14, relays 16 "and .17 conductors 28, 29 and 30 to the battery 1. It is evident from the above that more current flows through the winding 48 than through the winding 47 of the relay W, so that the magnetic fields of the relay do not balance and the resultant field raises the armature 38 to open the contact at 39, consequently breaking the circuit energizing the relay 33, and thereby causing the brakes to be applied and the motive power of the engine to be cut off. Similarly a ground on conductor 11, as indicated in dotted lines Y, causes the relay W to operate on account of having winding 47 of the relay W, this same 'current in returning to the battery 1 goes through the winding 48 of the relay and thus causes the same to operate as above set forth. A ground on the conductor 28,

as indicated in dotted lines V, allows some of the'current which has reached the engine frame by way of the winding 47 to reach the negative side of the battery 1 without passing throu h the winding 48 of the relay. This likewise causes the relay W to operate. A ground on conductor 14 is similar to one on conductor 11 and a ground on conductor 26 is similar to one on 28. In the event of the conductor 66 becoming grounded to the engine frame, a short circuit will be established through conductor 68 to the common return 28, with the contacts of the speedometer 67 closed, and thereby cause the differential relay W to operate since the current which passes through the winding 47 thereof will not pass-through winding 48. In a similar manner a ground on conductor 64 operates the relay .W through conductors 66, 68 and 28, with the speedometer contacts and keys 63 closed. A ground on either' conductors 51 or 52 operates the relay W through conductors 64, 66, 68 and 28, with the speedometer contacts,

key 63 and contacts 61 and 62 of valve L closed. A ground on conductor will shunt current through conductors 51, 64, 66 and 28 to the battery 1 without passing the same through the winding 48 of the relay W,

when the contacts of the speedometer, key 63, contacts 61and 62 of valve L and contacts 45 and 46 of the valve G are closed. A ground on wire 55 will cause the relay W to operate since current will pass, when the contacts 48 and 49 are closed, from the engine frame 8 through the conductor 56, the common return 28 to the battery 1. It is understood that all of the above elaborated grounds that may occur in the primary circuit caused more or less current to pass through one of either of the windings 47 or 48 of the relay W than the other, where-' upon the relay operates and breaks the circuit of the danger relay 33 normally closed by the armature 38. While the above considers only one position of the reversing switch S, it may be said the same protection will be formed in the other position of switch S, and that all the primary or low voltage wires are protected against grounds,

crosses, short circuits and break-outs in 111- sulation.

The foregoing illustrates applicants invention as applied and'used in an automatic train control system, as set forth in the copending application above-mentioned, and it is not the desire or intention of claimant to be limited to the particular arrangement shown, or to an arrangement embodying the various auxiliary features, except as particularly pointed out in the appending claims.

W hat is claimed is:

1. An automatic system of train control comprising: a controlling circuit, a source of electrical energy for said circuit, a controlled circuit for controlling the train controlling mechanism and a source of energy therefor, a differential relay interposed in said first circuit and having two coils either one of which is influenced by the misdirection of said first circuit to cause the operation of the train controlling mechanism.

2. An automatic system of train control comprising: a primary source of electrical energy grounded through the rails, a secondary source of electrical energy and a circuit including a main control relay for controlling the train mechanism, a differential relay connecting in circuit with the primary source and having its armature closing the main control relay circuit whereby any misdirection of flow of primary current will cause the operation of the armature of the differential relay to open the main relay circuit and stop the train.

3. An automatic system of train control cuit including a main control relay for controlling the train mechanism, a difierential relay connected in circuit with the primary source and having its armature closing the main control relay circuit, and whereby any misdirection of the flow of primary current will affect the armature to open the main relay and present a danger signal.

4:. An automatic system of train control including a primary circuit leading through the tender wheels, rails, and main wheels of the locomotive, a source of electrical energy for said circuit, a secondary circuit having a source of electrical energy, a main control relay in said circuit for controlling the train mechanism, a circuit breaker in said secondary circuit, a differential relay interposed in the primary circuit to control the circuit breaker, one of the windings of said relay being connected to the main wheel side while the other of said windings is connected to the tender avheel side thereof, whereby either coil may be influenced by the misdirection of the primary circuit to actuate the circuit breaker to cause an operation of the train controlling mechanism.

5. An automatic system of train control comprising: a primary circuit and a secondary circuit including a relay for the train controlling mechanism, a differential relay, the coils of which are interposed in the primary circuit, an armature for the diflerential relay to normally bridge the secondary circuit, whereby the misdirection of the flow of the primary current will cause the armature to open the secondary circuit thereby causing an operation of the train mechanism.

6. An automatic system of train control comprising: a primary circuit having a battery, the conductors of said circuit being connected respectively to the main wheels and tender Wheels of the locomotive, a secondary circuit including a battery and a main control relay for actuating the train controlling mechanism, a differential relay having its coils interposed between the conductors connected to the main wheels and tender Wheels of the locomotive, an armature for said relay normally bridging the secondary circuit, whereby the misdirection of flow of primary current will affect the coils of the relay and cause the armature to open the secondary circuit and stop the train.

7 An automatic system of train control comprising: electric circuits for controlling the train including a controlled circuit and a controlling circuit, a control relay in the controlled circuit for operating the train mechanism, and a differential relay in said controlling circuit for rupturing said controlled circuit and to cause said control relay to operate the train mechanism, upon a cross, short circuit, or break down in the insulation of said controlling circuit occurring.

8. A system of train control comprising: a traffic track, a train having two contacts establishing electrical connection between the train and track, a controlling circuit on the train having a source of energy, insulation on the train normally compelling the current of the controlling circuit to pass through a section of track from one contact to the other to complete said circuit, a difl erential relay in said circuit having one of its windings connected with one of said contacts and the other winding connected with the other of said contacts so that the current passing from one contact to the other through the track will pass through both windings of said relay to neutralize the same, a controlled circuit on the train for controlling the train mechanism and a circuit breaker in said controlled circuit to be operated by said relay when the latter is not neutralized, due to a cross or ground in said circuits.

9. An automatic system of train control comprising: a normally closed controlling circuit, a normally closed controlled circuit, train controlling means in said controlled circuit, means in said controlling circuit including two mutually nullifying paths of said circuit for energizing said means to.

open said controlled circuit and actuate said train controlling means upon any disturbance of the relative values of the current through said'paths due to the grounding of the circuit through either of said paths.

10. An automatic system of train control comprising: a train governing means, a circuit, means in said circui't for controlling the train governing means, track means cooperating with said circuit for causing the actuation of said train governing means, additional means in said circuit for controlling the train governing means including two mutually neutralizing paths for said circuit for energizing said additional means to cause the actuation of said train controlling means upon any unbalancing of the circuit through said paths due to the grounding of the circuit through either of said paths.

In testimony that I claim the foregoing as my own, l have hereto afiixed my signature in theprcsence of two witnesses.

GARDNER B. GRAY. 

